Titanium dioxide (TiO2) thin films were prepared on Galvanized Iron (GI) substrate by plasma-enhanced atomic layer deposition (PE-ALD) using tetrakis-dimethylamido titanium and O2 plasma to investigate the photocatalytic activities. The PE-ALD TiO2 thin films exhibited relatively high growth rate and the crystal structures of TiO2 thin films depended on the growth temperatures. TiO2 thin films deposited at 200 °C have amorphous phase, whereas those with anatase phase and bandgap energy about 3.2 eV were deposited at growth temperature of 250 °C and 300 °C. From contact angles measurement of water droplet, TiO2 thin films with anatase phase and Activ™ glass exhibited superhydrophilic surfaces after UV light exposure. And from photo-induced degradation test of organic solution, anatase TiO2 thin films and Activ™ glass decomposed organic solution under UV illumination. The anatase TiO2 thin film on GI substrate showed higher photocatalytic efficiency than Activ™ glass after 5 h UV light exposure. Thus, we suggest that the anatase phase in TiO2 thin film contributes to both superhydrophilicity and photocatalytic decomposition of 4-chlorophenol solution and anatase TiO2 thin films are suitable for self-cleaning applications.
Bibliographical noteFunding Information:
This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) ( KRF-2007-331-D00243 ) and POSCO Technical Research Laboratories , Blue Ocean Technology project ( 2008Y233 ). And one of the authors (Chang-Soo Lee) was financially supported by the second stage of the Brain Korea 21 project in 2008.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry